Trench hoe



Nov. 20, 1956 R. H. SLATER 2,771,201

/ TRENCH HOE Filed Sept. 4, 1955 2 Sheets-Sheet 1 l2 INVENTOR.

' RALEH H.- SLATER AGENT Nov. 20, 1956 R. H. SLATER TRENCH HOE 2 Sheets-Sheet 2 Filed Sept. 4, 1953 INVENTOR. RALPH H. SLATER United States Patent 9 TRENCH HOE Ralph H. Slater, Duluth, Minn. Application September 4, 1953, Serial No. 378,513 4 Claims. (Cl. 214-138) This invention relates to trench hoes, which are also called pull-shovels or back-diggers, and has special reference to an improved boom-stick-pitch brace relationshi l rench hoes have been in use for several years, having been originally intended for digging ditches where material or dirt excavated from the ditches is piled up alongside of the ditch for return into the ditch later. Trench hoes work very well in this capacity. However in late years, the trench hoe is being used more and more in digging operations where material excavated must be loaded on trucks or the like and hauled away. Some of these operations are basement digging, and trench digging, where a gravel or other special fill is required for the excavation.

Trench hoes are not very efficient when it comes to loading because of the fixed angle of the bucket relative to the stick. Loose granular or wet material spill from the bucket after it is raised far enough to clear the truck box to dump, and as soon as the bucket is pushed outwardly so that only a part of the load picked up gets into the truck, requiring more scooping operations to fill the truck. Obviously this wasted efiort is expensive. However, it is still less expensive to use a trench hoe for many types of digging operations because a trench hoe can dig a hole without getting into the hole, as is necessary with a power shovel.

It is therefor one of the principal objects of my invention is to provide means for increasing the efliciency of a trench hoe when loading trucks, and substantially eliminating spillage.

Another object is to provide for increased efficiency in a trench hoes digging operation.

A more specific object of my invention is to provide an improved mounting relationship between a trench hoe bucket, stick, and pitch brace whereby the angle of the bucket relative to the stick is progressively varied as the stick moves forwardly and rearwardiy during its operation.

Another object is to pivotally mount a trench hoe bucket on the lower end of the stick, and to provide a pair of spaced pitch braces which are pivotally mounted on the bucket in spaced relation to its mounting on the stick, the pitch braces being pivotally connected at their opposite ends to the boom in spaced relation to the pivotal mounting of the stick on the boom and on the opposite side of the stick whereby the pitch braces cross the stick.

These and other objects and advantages of my invention will become more apparent as the description proceeds.

In the accompanying drawing forming a part of this application:

Fig. l is a top plan view of the outer end of a trench hoe boom showing my invention.

Fig. 2 is a side elevational view of the boom and stick of a trench hoe showing my improved bucket and pitch brace mounting in full lines at the start of a digging cycle and comparing same with a conventional trench hoe shown in dotted lines.

Fig. 3 is a view similar to Fig. 2 showing the end of the digging cycle.

Fig. 4 is a view similar to Fig. 3 showing a modified form of my invention wherein the lower ends pitch braces are attached to the forward end of the bucket and the stick is attached to the rear end of the bucket. wise the attachment of the upper ends of the pitch braces and the stick to the boom are reversed.

Fig. 5 is a side elevational view of a trench hoe equipped in accordance with my invention and showing the digging cycle in dotted lines.

In the drawing, the reference numeral 1 indicates the cab or body of a trench hoe to which the boom 2 is pivotally attached at its lower end, all of which is conventional in a conventional trench hoe, the stick 3 is pivotally mounted on the outer end 4 of the boom 2 by means of a suitable pin 5. A cable 6 is connected to an extension 7 of the stick and is operated by conventional means, not shown, within the cab 1 of the trench hoe to pivot the stick so as to force the lower, or outer end 8 of the stick outwardly, or away from the cab 1. A second cable 9 is attached to the lower end 8 of the stick and is carried over a suitable pulley or sheave 10,

rotatably carried on the boom 2, to pull the lower end of the stick inwardly, or towards, the cab 1. This arrangement is conventional, and the trench hoe operated by operating suitable controls within the cab can pivot the stick on the boom as required for its digging. In a conventional trench hoe the boom 2 is provided with suitable means, not shown, whereby the outer end 4 of the boom may be raised and lowered for digging and discharging operations.

In my invention the bucket 11 is pivotally mounted on the lower end of the stick 3 by means of suitable spaced lugs 1212 and a pin 13 extending through the lugs 12 and the lower end of the stick. This provides a pivotal mounting for the bucket on the stick, and as shown in Figures 1 and 2, the stick is pivotally mounted adjacent the lip, or leading edge end of the bucket, while in Fig. 4 the stick is shown as being attached to the trailing edge of the bucket. This arrangement differs from conventional bucket mountings in that there is no pivoting of the bucket relative to the stick in a convention trench hoe.

In my device I provide a pair of pitch braces 1414, onev of which is pivotally mounted on each side of the boom by a common mounting pin 15 which extends through the boom and pivotally carries each of the pitch braces 14 at their upper ends. The pitch braces are carried in lateral alinement'with each other, and have their lower ends pivotally carried by suitable mounting lugs 16-16, and pins 17 extending through the lugs and the lower ends of the pitch braces. The lower ends 0: the pitch braces are pivotally mounted on the bucket i1 spaced relation to the pivotal mounting of the stick t( the bucket. In Figs. 2 and 3 the lower ends of the pitcl braces are carried adjacent the trailing edge of the bucket while in Fig. 4 the lower end of the pitch braces ar carried adjacent to the forward end of the bucket. Th upper ends of the pitch braces in Figs. 2 and 3 are pit otally mounted in rearwardiy spaced relationto pivt pin 5 of the stick. In Fig. 4 the upper ends of the pitc braces are carried by an extension 18 of the boom, said e: tension being forwardly of the pivot pin 5 of the stic It is thus deemed apparent that the pitch braces 1 and the stick, are crossed.

The crossing of the pitch braces with the stick ditfe from the conventional trench hoe wherein the pitch brac 19 are carried and secured between the bucket and t boom directly to the stick itself, thus providing a rig and fixed angular relation between the stick and the In the present invention the angle of disposily illustrate in solid lines the relative positions of the bucket during the digging cycle when the present invention is employed and in dotted lines the positions taken by a conventionally mounted bucket.

cause of the rapidly changing angle of the bucket due to the pitch brace installation. It is deemed readily aparent that the bucket when held in the position shown might lose some of its material. Whereas in the conventional installation the bucket begins losing and spilling material practically as soon as the stick is moved forwardly and outwardly, or dumping into the truck.

each digging cycle, than will a conventional trench hoe, especially when loading trucks or other vehicles where the points of dumping'are substantially above the ground level.

In Fig. 4 the pitch braces cross the stick, and the operation of the device is similar to that of Figs. 2 and 3. However, in the modified form of the invention, the stick is pivotally mounted adjacent the trailing edge of the bucket, and the pitch braces are pivotally mounted adjacent the lip edge of the bucket. The crossing of the pitch braces and the stick makes it necessary to add an extension 18 to the boom beyond the pivot point of the stick, the pitch braces being pivotally mounted adjacent the outer end of extension 18, beyond the pivot point of the stick.

As shown in the drawings suitably spaced openings 24 may be provided on the pitch braces and/or the boom, whereby the angle of attack of the bucket may be regulated as desired to accommodate varying digging requirements. It is deemed apparent that the advantages of 'the cross pitch braces andstick, whereby the angle of the bucket is progressively varied as the digging cycle proceeds,-will be maintained even though the adjustment feature is employed.

Having thus described my invention, what I claim is:

the opposite ends thereof for pivotally moving said stick stick on the boom.

References Cited in the file of this patent UNITED STATES PATENTS 1,144,793 Rood June 29, 1915 1,703,063 Dorward Feb. 19, 1929 2,106,402 Carlesimo Jan. 25, 1938 

